Cosmologies from higher-order string corrections

Abstract

We study cosmologies based on low-energy effective string theory with higher-order string corrections to a tree-level action and with a modulus scalar field (dilaton or compactification modulus). In the presence of such corrections it is possible to construct nonsingular cosmological solutions in the context of Pre-Big-Bang and Ekpyrotic universes. We review the construction of nonsingular bouncing solutions and resulting density perturbations in Pre-Big-Bang and Ekpyrotic models. We also discuss the effect of higher-order string corrections on dark energy universe and show several interesting possibilities of the avoidance of future singularities.

15 pages, 2 figures, References are added, plenary talk at Pomeranian Workshop in Fundamental Cosmology (COSMOFUN 05), Pobierowo, Poland, 1-6 September 2005

References in corpus (57)

• Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
• Measurements of Omega and Lambda from 42 High-Redshift Supernovae
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Determination of Cosmological Parameters
• Type Ia Supernova Discoveries at z>1 From the Hubble Space Telescope: Evidence for Past Deceleration and Constraints on Dark Energy Evolution
• A Phantom Menace? Cosmological consequences of a dark energy component with super-negative equation of state
• Phantom Energy and Cosmic Doomsday
• Coupled Quintessence
• The Ekpyrotic Universe: Colliding Branes and the Origin of the Hot Big Bang
• Generating the curvature perturbation without an inflaton
• Can the dark energy equation-of-state parameter w be less than -1?
• Properties of singularities in (phantom) dark energy universe
• Late-time cosmology in (phantom) scalar-tensor theory: dark energy and the cosmic speed-up
• Pre-Big-Bang in String Cosmology
• The Pre-Big Bang Scenario in String Cosmology
• Adiabatic CMB perturbations in pre-big bang string cosmology
• Effects of Cosmological Moduli Fields on Cosmic Microwave Background
• Cosmic Evolution in a Cyclic Universe
• Gauss-Bonnet dark energy
• Scaling solutions in general non-minimal coupling theories
• A Cyclic Model of the Universe
• The final state and thermodynamics of dark energy universe
• Cosmological Dynamics of Phantom Field
• Is there Supernova Evidence for Dark Energy Metamorphosis ?
• Superstring Cosmology
• Singularity-free cosmological solutions of the superstring effective action
• Duality Invariance of Cosmological Perturbation Spectra
• Quantum escape of sudden future singularity
• Density Perturbations in the Ekpyrotic Scenario
• Towards a non-singular pre-big bang cosmology
• Coupled dark energy: Towards a general description of the dynamics
• The foundations of observing dark energy dynamics with the Wilkinson Microwave Anisotropy Probe
• The fate of (phantom) dark energy universe with string curvature corrections
• On matching conditions for cosmological perturbations
• On the Construction of Nonsingular Pre-Big-Bang and Ekpyrotic Cosmologies and the Resulting Density Perturbations
• The primordial curvature perturbation in the ekpyrotic Universe
• Dark energy and cosmological solutions in second-order string gravity
• A Model of Graceful Exit in String Cosmology
• Singularity-free cosmological solutions in quadratic gravity
• On the Spectrum of Fluctuations in an Effective Field Theory of the Ekpyrotic Universe
• Cosmological perturbations through a simple bounce
• Metric Perturbations in Dilaton-Driven Inflation
• Vacuum fluctuations in axion-dilaton cosmologies
• Adiabatic perturbations in pre big bang models: matching conditions and scale invariance
• Cosmological Perturbations in a Big Crunch/Big Bang Space-time
• Evolution of cosmological perturbations in non-singular string cosmologies
• Perturbations in bouncing cosmologies: dynamical attractor vs scale invariance
• The graceful exit in pre-big bang string cosmology
• Cosmological structure problem of the ekpyrotic scenario
• Perturbations in a non-singular bouncing Universe
• The failure of cosmological perturbation theory in the new ekpyrotic and cyclic ekpyrotic scenarios
• Loop corrections and graceful exit in string cosmology
• Quantum Fields in a Big Crunch/Big Bang Spacetime
• Cosmological perturbations across a curvature bounce
• Density perturbations in the Ekpyrotic Universe and string-inspired generalizations
• Nature of singularities in anisotropic string cosmology
• Generality of Singularity Avoidance in Superstring Theory: Anisotropic Case
• Cosmological Structure Problem of the Pre-Big Bang Scenario

Cited by in corpus (13)

• Dynamics of dark energy
• Modified Gravity and Cosmology
• f(R) theories
• Matter density perturbations and effective gravitational constant in modified gravity models of dark energy
• Gauss-Bonnet Quintessence: Background Evolution, Large Scale Structure and Cosmological Constraints
• String-inspired cosmology: Late time transition from scaling matter era to dark energy universe caused by a Gauss-Bonnet coupling
• Delicate f(R) gravity models with disappearing cosmological constant and observational constraints on the model parameters
• Non-local SFT Tachyon and Cosmology
• Cosmic acceleration with a negative cosmological constant in higher dimensions
• Post-Newtonian expansion for Gauss-Bonnet Gravity
• A Note on the Viability of Gauss-Bonnet Cosmology
• Stringy corrections to a time-dependent background solution of string and M-Theory
• Non-critical anisotropic Bianchi type $I$ string cosmology with ${\alpha }^{\prime }$-corrections